On Fri, Jan 10, 2020 at 10:11:23AM -0800, Vivek Kasireddy wrote:
> Parsing the i2c element is mainly done to transfer the payload from the
> MIPI sequence block to the relevant slave device. In some cases, the
> commands that are part of the payload can be used to turn on the backlight.
>
> This patch is actually a refactored version of this old patch:
> https://lists.freedesktop.org/archives/intel-gfx/2014-December/056897.html
>
> In addition to the refactoring, the original patch is augmented by looking up
> the i2c bus from ACPI NS instead of relying on the bus number provided
> in the VBT.
>
> This patch was tested on Aava Mobile's Inari 10 tablet. It enabled
> turning on the backlight by transfering the payload to the device.
>
> v2:
> - Add DRM_DEV_ERROR for invalid adapter and failed transfer and also
> drop the DRM_DEBUG that existed originally. (Hans)
> - Add two gotos instead of one to clean things up properly.
>
> v3:
> - Identify the device on which this patch was tested in the commit
> message (Ville)
>
> Cc: Hans de Goede <hdego...@redhat.com>
> Cc: Nabendu Maiti <nabendu.bikash.ma...@intel.com>
> Cc: Matt Roper <matthew.d.ro...@intel.com>
> Cc: Bob Paauwe <bob.j.paa...@intel.com>
> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> Reviewed-by: Hans de Goede <hdego...@redhat.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasire...@intel.com>
Since v3 is identical to v2 except for the commit message, I think we
can apply this based on v2's CI results. The only CI failure was an
incomplete on a non-DSI TGL system and the incomplete happened long
after the VBT parsing changes here would have had any effect.
Applied to dinq. Thanks for the patch and review.
Matt
> ---
> drivers/gpu/drm/i915/display/intel_dsi.h | 3 +
> drivers/gpu/drm/i915/display/intel_dsi_vbt.c | 99 +++++++++++++++++++-
> 2 files changed, 100 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dsi.h
> b/drivers/gpu/drm/i915/display/intel_dsi.h
> index 7481a5aa3084..6cef1356b4e6 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsi.h
> +++ b/drivers/gpu/drm/i915/display/intel_dsi.h
> @@ -69,6 +69,9 @@ struct intel_dsi {
> /* number of DSI lanes */
> unsigned int lane_count;
>
> + /* i2c bus associated with the slave device */
> + int i2c_bus_num;
> +
> /*
> * video mode pixel format
> *
> diff --git a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> index 0032161e0f76..89fb0d90b694 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> +++ b/drivers/gpu/drm/i915/display/intel_dsi_vbt.c
> @@ -86,6 +86,12 @@ static struct gpio_map vlv_gpio_table[] = {
> { VLV_GPIO_NC_11_PANEL1_BKLTCTL },
> };
>
> +struct i2c_adapter_lookup {
> + u16 slave_addr;
> + struct intel_dsi *intel_dsi;
> + acpi_handle dev_handle;
> +};
> +
> #define CHV_GPIO_IDX_START_N 0
> #define CHV_GPIO_IDX_START_E 73
> #define CHV_GPIO_IDX_START_SW 100
> @@ -378,11 +384,98 @@ static const u8 *mipi_exec_gpio(struct intel_dsi
> *intel_dsi, const u8 *data)
> return data;
> }
>
> +static int i2c_adapter_lookup(struct acpi_resource *ares, void *data)
> +{
> + struct i2c_adapter_lookup *lookup = data;
> + struct intel_dsi *intel_dsi = lookup->intel_dsi;
> + struct acpi_resource_i2c_serialbus *sb;
> + struct i2c_adapter *adapter;
> + acpi_handle adapter_handle;
> + acpi_status status;
> +
> + if (intel_dsi->i2c_bus_num >= 0 ||
> + !i2c_acpi_get_i2c_resource(ares, &sb))
> + return 1;
> +
> + if (lookup->slave_addr != sb->slave_address)
> + return 1;
> +
> + status = acpi_get_handle(lookup->dev_handle,
> + sb->resource_source.string_ptr,
> + &adapter_handle);
> + if (ACPI_FAILURE(status))
> + return 1;
> +
> + adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
> + if (adapter)
> + intel_dsi->i2c_bus_num = adapter->nr;
> +
> + return 1;
> +}
> +
> static const u8 *mipi_exec_i2c(struct intel_dsi *intel_dsi, const u8 *data)
> {
> - DRM_DEBUG_KMS("Skipping I2C element execution\n");
> + struct drm_device *drm_dev = intel_dsi->base.base.dev;
> + struct device *dev = &drm_dev->pdev->dev;
> + struct i2c_adapter *adapter;
> + struct acpi_device *acpi_dev;
> + struct list_head resource_list;
> + struct i2c_adapter_lookup lookup;
> + struct i2c_msg msg;
> + int ret;
> + u8 vbt_i2c_bus_num = *(data + 2);
> + u16 slave_addr = *(u16 *)(data + 3);
> + u8 reg_offset = *(data + 5);
> + u8 payload_size = *(data + 6);
> + u8 *payload_data;
> +
> + if (intel_dsi->i2c_bus_num < 0) {
> + intel_dsi->i2c_bus_num = vbt_i2c_bus_num;
> +
> + acpi_dev = ACPI_COMPANION(dev);
> + if (acpi_dev) {
> + memset(&lookup, 0, sizeof(lookup));
> + lookup.slave_addr = slave_addr;
> + lookup.intel_dsi = intel_dsi;
> + lookup.dev_handle = acpi_device_handle(acpi_dev);
> +
> + INIT_LIST_HEAD(&resource_list);
> + acpi_dev_get_resources(acpi_dev, &resource_list,
> + i2c_adapter_lookup,
> + &lookup);
> + acpi_dev_free_resource_list(&resource_list);
> + }
> + }
>
> - return data + *(data + 6) + 7;
> + adapter = i2c_get_adapter(intel_dsi->i2c_bus_num);
> + if (!adapter) {
> + DRM_DEV_ERROR(dev, "Cannot find a valid i2c bus for xfer\n");
> + goto err_bus;
> + }
> +
> + payload_data = kzalloc(payload_size + 1, GFP_KERNEL);
> + if (!payload_data)
> + goto err_alloc;
> +
> + payload_data[0] = reg_offset;
> + memcpy(&payload_data[1], (data + 7), payload_size);
> +
> + msg.addr = slave_addr;
> + msg.flags = 0;
> + msg.len = payload_size + 1;
> + msg.buf = payload_data;
> +
> + ret = i2c_transfer(adapter, &msg, 1);
> + if (ret < 0)
> + DRM_DEV_ERROR(dev,
> + "Failed to xfer payload of size (%u) to reg
> (%u)\n",
> + payload_size, reg_offset);
> +
> + kfree(payload_data);
> +err_alloc:
> + i2c_put_adapter(adapter);
> +err_bus:
> + return data + payload_size + 7;
> }
>
> static const u8 *mipi_exec_spi(struct intel_dsi *intel_dsi, const u8 *data)
> @@ -683,6 +776,8 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16
> panel_id)
> intel_dsi->panel_off_delay = pps->panel_off_delay / 10;
> intel_dsi->panel_pwr_cycle_delay = pps->panel_power_cycle_delay / 10;
>
> + intel_dsi->i2c_bus_num = -1;
> +
> /* a regular driver would get the device in probe */
> for_each_dsi_port(port, intel_dsi->ports) {
> mipi_dsi_attach(intel_dsi->dsi_hosts[port]->device);
> --
> 2.21.1
>
--
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795
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